Pandya Chirayu D, Vekaria Hemendra, Joseph Binoy, Slone Stacey A, Gensel John C, Sullivan Patrick G, Miller Brandon A
Department of Neurosurgery, University of Kentucky, Lexington, Kentucky; Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky.
Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky.
Transl Res. 2021 May;231:13-23. doi: 10.1016/j.trsl.2021.01.005. Epub 2021 Jan 15.
Oligodendrocyte progenitor cells (OPCs) in the infant brain give rise to mature oligodendrocytes that myelinate CNS axons. OPCs are particularly vulnerable to oxidative stress that occurs in many forms of brain injury. One common cause of infant brain injury is neonatal intraventricular hemorrhage (IVH), which releases blood into the CSF and brain parenchyma of preterm infants. Although blood contains the powerful oxidant hemoglobin, the direct effects of hemoglobin on OPCs have not been studied. We utilized a cell culture system to test if hemoglobin induced free radical production and mitochondrial dysfunction in OPCs. We also tested if phenelzine (PLZ), an FDA-approved antioxidant drug, could protect OPCs from hemoglobin-induced oxidative stress. OPCs were isolated from Sprague Dawley rat pups and exposed to hemoglobin with and without PLZ. Outcomes assessed included intracellular reactive oxygen species levels using 2',7'-dichlorodihydrofluorescein diacetate (DCF-DA) fluorescent dye, oxygen consumption using the XFe96 Seahorse assay, and proliferation measured by BrdU incorporation assay. Hemoglobin induced oxidative stress and impaired mitochondrial function in OPCs. PLZ treatment reduced hemoglobin-induced oxidative stress and improved OPC mitochondrial bioenergetics. The effects of hemoglobin and PLZ on OPC proliferation were not statistically significant, but showed trends towards hemoglobin reducing OPC proliferation and PLZ increasing OPC proliferation (P=0.06 for both effects). Collectively, our results indicate that hemoglobin induces mitochondrial dysfunction in OPCs and that antioxidant therapy reduces these effects. Therefore, antioxidant therapy may hold promise for white matter diseases in which hemoglobin plays a role, such as neonatal IVH.
婴儿大脑中的少突胶质前体细胞（OPCs）可分化为成熟的少突胶质细胞，这些细胞会为中枢神经系统轴突形成髓鞘。OPCs特别容易受到多种形式脑损伤中出现的氧化应激的影响。婴儿脑损伤的一个常见原因是新生儿脑室内出血（IVH），它会将血液释放到早产儿的脑脊液和脑实质中。尽管血液中含有强大的氧化剂血红蛋白，但血红蛋白对OPCs的直接影响尚未得到研究。我们利用细胞培养系统来测试血红蛋白是否会诱导OPCs产生自由基和线粒体功能障碍。我们还测试了一种经美国食品药品监督管理局（FDA）批准的抗氧化药物苯乙肼（PLZ）是否能保护OPCs免受血红蛋白诱导的氧化应激。从Sprague Dawley大鼠幼崽中分离出OPCs，并在有或没有PLZ的情况下使其暴露于血红蛋白中。评估的结果包括使用2',7'-二氯二氢荧光素二乙酸酯（DCF-DA）荧光染料检测细胞内活性氧水平、使用XFe96 Seahorse分析仪检测氧气消耗以及通过BrdU掺入法检测增殖情况。血红蛋白诱导了OPCs的氧化应激并损害了线粒体功能。PLZ处理降低了血红蛋白诱导的氧化应激并改善了OPCs的线粒体生物能量学。血红蛋白和PLZ对OPCs增殖的影响在统计学上不显著，但显示出血红蛋白降低OPCs增殖而PLZ增加OPCs增殖的趋势（两种影响的P值均为0.06）。总体而言，我们的结果表明血红蛋白会诱导OPCs的线粒体功能障碍，而抗氧化治疗可减轻这些影响。因此，抗氧化治疗可能对血红蛋白起作用的白质疾病（如新生儿IVH）具有治疗前景。
